Chemokine is known as a basic protein which has chemotaxis and an activating activity against endogenous leucocytes and also has strong heparin-binding abilities. It is now considered that chemokine is associated with not only control of infiltration of specific leucocytes upon inflammatory and immune responses, but also development, homing of lymphocytes under physiological conditions and migration of hemocyte precursor cells and somatic cells.
Differentiation, proliferation and cell death of blood cells are controlled by various cytokines. Inflammation occurs at a local region in a living body. Differentiation and maturation of lymphocytes, and the like are carried out at a specific site. More particularly, required various cells migrate and accumulate in the specific site and a sequence of inflammatory and immune responses arise. Thus, in addition to differentiation, proliferation and death of cells, cell migration is also an essential phenomenon to an immune system.
In the living body, migration of blood cells start with sifting hemopoiesis that started at AGM (Aorta Gonad Mesonephros) region via fetal liver to permanent hematopoiesis at bone marrow in a development course. Moreover, precursors of T cells and thymus dendritic cells migrate from fetal liver into bone marrow and then into the thymus gland. They differentiate under thymus environment. The T cells are subjected to clonal selection migrates into secondary lymphoid tissues, where they contribute to immune responses in periphery. Skin Langerhans cells that caught antigen, thereby undergone activation and differentiation migrate to T cell region in a topical lymph node, where they activate naive T cells therein as dendritic cells. The memory T cells again perform its homing into the lymph node via lymphatic and blood vessels. In addition, B cells, T cells in intestinal epithelia, γδT cells, NKT cells, and dendritic cells migrate from bone marrow not via thymus, differentiate and contribute to immune responses.
Chemokine is closely associated with such a migration of the various cells. For example, SDF-1 (Stromal cell derived factor-1) and its receptor, CXCR4 also act on various immune- and inflammatory reactions. For example, they have been reported to be associated with accumulation and activation of CD4+T cells in a synovial membrane from a human patient suffering from rheumatoid arthritis (J. Immunol., 165, 6590-6598 (2000)). In addition, in a CIA model mouse, CXCR4 inhibitor inhibited accumulation of leucocytes in a joint and dramatically reduced arthritis score (J. Immunol., 167, 4648-4692 (2001)). In a mouse OVA-induced airway hypersensitive model, an anti-CXCR4 antibody reduced the number of eosinophiles accumulating in pulmonary interstitial tissues and prevented airway hypersensitivity (J. Immunol., 165, 499-508 (2000)). In a murine model of bleomycin-induced pulmonary damage, an anti-SDF-1 antibody prevented fibrocellular infiltration to lung and fibrosis of lung tissue (J. Cli. I, 114, 438-446 (2004)). In a murine model of retinopathy, an anti-SDF-1 antibody prevented infiltration of vascular endothelial precursor cell to retina and retinal neovascularization (J. Cli. I, 115, 86-93 (2005)).
There has been reported that SDF-1 and its receptor, CXCR4 play an important role in maintaining hemopoietic stem cells in bone marrow (J. Exp. Med., 185, 111-120 (1997), Blood, 97, 3354-3360 (2001)). Accordingly, control of SDF-1 and CXCR4 is expected to modulate recruitment of hemopoietic stem cells to peripheral blood and are useful for peripheral blood stem cell transplantation and reproduction transplantation treatment.
SDF-1 and CXCR4 are associated with proliferation and infiltration of various cancer cells such as breast cancer, prostate cancer, ovarian cancer and brain cancer (Nature, 410, 50-56 (2001), Cancer Res., 62, 1832-1837 (2002), Cancer Res., 62, 5930-5938 (2002)). In a model of transplanting a human breast cancer cell strain into a SCID mouse, an anti-CXCR4 antibody prevented metastasis of breast cancer cells to lung (Nature, 410, 50-56 (2001)). And also, an anti-SDF-1 antibody prevented neoangiogenesis of tumor periphery and tumor cell proliferation (Cell, 121, 335-348 (2005)). Inhuman ovarian epithelial tumor, highly expression of SDF-1 brings in plasmacytoid precursor dendritic cells which decrease T cell's function and suppresses tumor immune (Nat. Med., 12, 1339 (2001)). Moreover, SDF-1 is associated with proliferation and migration of non-Hodgkin's lymphoma cells, and in a model of transferring a human non-Hodgkin's lymphoma cells into a NOD/SCID mouse, an anti-CXCR4 antibody inhibited proliferation of the tumor cells and improved mouse mortality (Cancer Res., 62, 3106-3112 (2002)). Also, a small-molecule antagonist of CXCR4 increased murine intracranial medulloblastoma xenografts apoptosis and inhibits the proliferation of tumor (Proc. Nat. Acad. Sci. USA, 100, 13513-13518 (2003)).
SDF-1 and CXCR4 play an important role for formation of hippocampus dentate gyrus granulocyte, that is essential for memory and learning and are associated with development of a disease associated with adult plasticity and pathology of hippocampus, for example Alzheimer's disease, stroke and epilepsy (Development, 129, 4249-4260 (2002), Trends in Neuroscience, 25, 548-549 (2002)).
SDF-1 and CXCR4 are essential for a function of self-reactive B cells associated with development of diabetes. In NOD mouse, an anti-SDF-1 antibody reduced blood glucose level and the number of mature IgM+B cells in a periphery tissue (Immunology, 107, 222-232 (2002)). In a human arteriosclerotic plaque, SDF-1 was highly expressed and activated blood platelets (Circ. Res., 86, 131-138 (2000)).
In addition, the results of SDF-1/CXCR4 knock-out mice showed that SDF-1 is essential for functions of central nervous system, heart and vessels of gastrointestinal tract in addition to lymphocytes (Nature, 382, 635-639 (1996), Nature, 393, 591-594 (1998), Nature, 393, 595-599 (1998)). Accordingly, it may be associated with a disease of these tissues.
Thus, chemokine receptors are expressed at various specific cells and at a specific time. They are largely associated with the control of inflammatory- and immune-responses through a mechanism by which their effector cells accumulate in a site where chemokine is produced.
Acquired immunodeficiency syndrome (also called AIDS) that caused by infection of human immunodeficiency virus (hereinafter abbreviated to HIV) is one of diseases for which therapies are the most eagerly desired lately. Once HIV infection has been established in a main target cell, CD4+ cell, HIV repetitively proliferates in a patient's body and in the event deathly destroys T cells responsible for immunological functions by necrosis. In this process, immunological functions are gradually deteriorated, various immunocompromised states become to develop such as fever, diarrhea and swelling of a lymph node, and various opportunistic infections such as carinii pneumonia are easily complicated. It is well known that such a state is the onset of AIDS and induces malignant tumors such as Kaposi's sarcoma and becomes severe.
Currently, there are tried various preventive and therapeutic treatments for AIDS as follows: for example, (1) inhibition of HIV proliferation by administration of reverse transcriptase inhibitors and protease inhibitors, and (2) prevention or alleviation of opportunistic infections by administration of an immunostimulant, etc.
HIV mainly infects helper T cells which play a key role in the immune system. Since 1985, it has been known that in this process HIV utilizes a membrane protein CD4 that is expressed on the membrane of T cells (Cell, 52, 631 (1985)). CD4 molecule consists of 433 amino acid residues and is expressed in macrophages, some B cells, vascular endothelial cells, Langerhans cells in skin tissues, dendritic cells located in lymphatic tissues, glia cells of central nervous system and the like in addition to mature helper T cells. However, as it becomes obvious that HIV infection cannot be established with only CD4 molecule, the possible presence of some factor that is responsible for infection of cell with HIV, other than CD4 molecule, has been suggested.
In 1996, a cell membrane protein called Fusin has been identified as a factor responsible for HIV infection other than a CD4 molecule (Science, 272, 872 (1996)). This Fusin molecule has been demonstrated to be a receptor for SDF-1, namely, CXCR4. In addition, it has been shown that SDF-1 specifically inhibits infection of T cell-directed (X4) HIV in vitro (Nature, 382, 829 (1996), Nature, 382, 833 (1996)). This may be considered that SDF-1 binds to CXCR4 prior to HIV, thereby taking away a scaffold for infecting a cell from HIV resulting in inhibition of HIV infection.
Also, at the same period, there has been found that another chemokine receptor CCR5, that is a receptor for RANTES, MIP-1α, and MIP-1β, is utilized at infection of macrophage-directed (R5) HIV (Science, 272, 1955 (1996)).
Accordingly, those which can compete with HIV for CXCR4 and CCR5 or those which bind to a HIV virus and prevent for said virus from binding to CXCR4 and CCR5 may be a HIV infection inhibitor. In addition, there is a case where a low molecular weight compound discovered as a HIV infection inhibitor was showed to be indeed an antagonist of CXCR4 (Nature Medicine, 4, 72 (1998)).
As described above, compounds having an antagonistic activity against CXCR4 is effective, such as, for prevention and/or treatment of inflammatory and immune diseases, allergic diseases, infections, particularly HIV infection, and diseases associated with the infection, psychoneurotic diseases, cerebral diseases, cardiovascular diseases, metabolic diseases, cancerous diseases and the like. Also, the compounds are useful for cell medical treatment and regeneration therapy.
In patent literature 1, it is disclosed that a compound represented by formula (a):

wherein ring A1a represents a 5- to 10-membered nitrogen-containing saturated heterocyclic ring which may have a substituent(s) or a 5- to 10-membered nitrogen-containing heterocyclic ring which may have a substituent(s), and have a double bond;
ring B1a represents a 6- to 11-membered nitrogen-containing mono- or bicyclic heterocyclic ring which may have a substituent(s);
Ga represents a bond or a spacer having a main chain of 1 to 3 atom(s);
ring Ja represents a 4- to 7-membered nitrogen-containing heterocyclic ring which may have a substituent(s); and
Wa represents a hydrogen atom, a hydrocarbon group which may have a substituent(s) or a heterocyclic ring group which may have a substituent(s) (only required portions were extracted.), or a salt thereof, an N-oxide thereof or a solvate thereof, or a prodrug thereof is useful as CXCR4 regulator.
[Patent literature 1] WO2004/052862